Source Code is what makes software applications work. It is the code that programmers write, “telling” the application what to do.
Using Open Source software, the user can freely change the way the software works. The user can change the way it looks, make it more efficient, and tailor it to the organization’s needs. An Open Source license gives you full rights to the software.
Propriety Software is the opposite of Open Source. Here, the source code is hidden and protected and you are not given access to it. Only people who have special access can modify the code. There are terms and conditions to which users must agree before being permitted to use it.
To illustrate: Microsoft Word is propriety software. One cannot obtain the source code and publish their word processing tool.
Psst,,, This entire site is running on Open Source software. We use WordPress, the most popular CMS/website authoring system out there.
Read more about Open Source:
Great article in WIRED magazine Open Source Article in TechCrunch